Tunnel-support.



G. G. FINLAYSON 8: J. N. GAIN.

Patented July 5, 1910.

WITNESSES ATTORNEYS UNITED STATESWPATENT OFFICE.

cnRIsTorHER COLUMBUS FINLAYSON AND JAMES NATHAN cam, on RI sBEE,

ARIZONA TERRITORY.

TUNNEL-sUrroRT.

Specification of Letters Patent.

Patented July 5, 1910.

Application filed October 27, 1909. Serial No. 524,825.

To all whom it may concern:

Be it known that we, CIIRISTOPIIER G. 'FINLAYSON, a citizen of the United States,

and JAMES N. CAIN, a subject of the King of England, and residents of Bisbee, in the county of Cochise and Territory of Arizona, have invented certain new and useful Improvements in Tunnel-Supports, of which the following is a specificatlon.

Our invention is an improvement in tunnel supports, and consists in certain novel constructions, and combinations of parts, hereinafter described and claimed.

The object of the invention is to provide an improvedform of drift support for mining purposes, which will be strong, durable and economical in construction, which will consists of few parts, and which may be cheaply constructed, and will require no change in the usual methods of mining.

Referring to the drawings forming a part hereof, Figure l is a transverse section of a section of the improved support, and Fig. 2 is a vertical section.

In driving drifts or tunnels in metal mining, the walls of the tunnel are subject to pressure from every side, and the support for the wall should be approximately equal in every direction. The heaviest pressure is however vertically downward, and the next heaviest vertically upward, while of course the pressure on each side of the tunnel or drift is approximately the same. A perfect support must necessarily have the greatest power of resistance in the directions above set forth. The supports ordinarily used are in sections of six or seven feet in length, and

are placed as soon as the material is exca- A vated, or in some cases a portion of the section is placed before the excavation is com menced. The embodiment of the invention shown in the drawings is adapted to be constructed and used in the same manner, and

comprises a plurality of substantially ellip-- tical metal frames, which form the base of the support, and a system of lagging or siding in connection with the frames.

Each of the frames-is composed of I bars, and is formed in two similar sections A and B, and the ends of the sections are connected by fish plates C, and bolts D, the plates being lapped on the adjacent ends of the-sections, and the bolts passed through registering openings in the plates and I bars.

The complete frames are substantially egg-shaped as shown in Fig. 1, and are arranged transversely of the drift or tunnel, with the large end downward, at intervals of six or seven feet. The lagging consisting of strips E is placed longitudinally of the drift, with the ends of the strips engaging the frames. Each strip engages one frame with one end, and the adjacent frame with the other, and the strips are spaced apart slightly laterally,- and are omitted at the bottom and for a short distance up the sides. The arrangement is however in. accordance with 'the conditions, and in some cases it might be necessary to make the laggin complete. The frames are also connecte with each other by means of rods G having threaded ends H which extend through registering openings in the frames, and are engaged by nuts K. The bolts prevent lateral movement of the frames, thus preventing displacement of the lagging.

In using the improved structure, the sections of the frame are placed, and secured together by the fish plates and bolts. The bolts G are then inserted, and secured in. place by the nuts K, after which the lagging E is placed in position. The ties M are placed, usually on the floor of the tunnel, and the rails N are secured to the ties in the usual manner. When the lagging is omitted from the bottom of the frames, the said bot-toms may be sunk in the floor of the tunnel.

It will be evident from the description that each frame is substantially oval in form and consists of a plurality of arches, each of which is especially shaped for the relative amount of pressure to which it will be subjected. At the top the radius of the arch is short, while at the sides it is long, thus providing a maximum amount of strength and head room with a minimum of material. The radiusof. the bottom arch is also greater than that of the top arch.

We claim 1. A tunnel or drift supporting structure comprising a plurality of frames, each of which is composed of four arches, the radius of the end arches being of lesser length than the radius of the side arches, and the radius of the lower end arch being of greater length than that of the upper arch, each of said frames being divided at its top and bottom into substantially similar sections,

fish plates overlapping the adjacent ends of the s'ection sf and bolts securingvthe' fish plates on-the sections, bolts connectingthe rames, and a plurality of strips each haying its ends engaging adjacent frames;

- fied, a substantially annular frame, oval in consisting of outer faces of he frames.

.connecting the ends of the sections, a connection betw'een'the frames, and lagging arallel strips engaging the 3; A structureof the character specified,

comprising a plurality of frames, each of which is oval inform and presents a convex surface at every point of its periphery, a connectionbetween the frames, and a'icovering for the frames. v

4. Ina structure of the'character speciform, and presenting a continuous curve.

5. In a structure of the character specieesasae fied, an annular, frame whose sides are formed on equal arcs,the base on an arc.- of

less radius than the arc of the sides, and the tap on an arc of less radius than the arc of t e base. 6.; In a structure of the character specified, an annular substantially elliptical frame, one end of the frame bein" formed,

7. In a structure of the character sgaecified, a, supporting frame, annular in orm, and forme from a plurality of arm merging into each other at their ends, the arc of the base being of greater diameter than the arc of the. top.

'8; A. frame substantially as herein described in oval form with its major axis ver tical and having its lower, or baseportion arched downwardly.

CHRISTOPHER. COLUMBUS FINLAYSON. JAMES NAI'HAN GAIN.

Witnesses:

DONALD G. Ross,

CHARLES R. Monroo'r.

on an arc of greater radius than t e other. a 

